1. Field of the Invention
The present invention relates to a weather strip, which is attached to a vehicle body around an opening that is opened and closed by a door, such as an opening trim weather strip.
2. Description of Related Arts
A weather strip used for a vehicle includes a generally U-shaped trim and a hollow seal, which extends from a side wall or a bridging wall of the trim. Such a weather strip is required to seal gaps between the vehicle body and the door when the door is closed. In other words, such a weather strip must be airtight and waterproof when the door is closed.
To form the weather strip, extrusion molding is performed to manufacture an elongated, extruded portion. The elongated portion is then bent in a looped manner so that a predetermined sealing is obtained around an entire opening. Alternatively, a plurality of extruded portions are connected to each other and bent in a looped manner. The two ends of the single extruded portion or the two ends of the connected extruded portions are then arranged in a mold. Injection molding is then performed to form a molded portion that joins the two ends. This completes the formation of the weather strip (first related art example).
In the weather strip of the first related art example, a hollow seal must also be formed on the molded portion between the ends of the extruded portion. Thus, referring to FIG. 12, a core 103 must be arranged in a cavity of a molding device to form a hollow seal 102 when molding a molded portion 101. The core 103 has ends 104 that are fitted in opposing ends 106 of extruded portions 105a, 105b to prevent molding material from entering the extruded portions 105a, 105b. After the molded portion 101 is molded, most of the core 103 is enveloped by a material such as rubber. Thus, a slit must be provided on a hollow seal 102 of one of the extruded portions 105a, 105b or the hollow seal 102 of the molded portion 101 to remove the core 103 from the hollow seal 102 of the molded portion 101.
In the example of FIG. 12, a slit 107 is provided in a side wall 102a of the hollow seal 102 near the end 106 of the extruded portion 105a. In this case, a removing handle 108 is attached to the core 103. The core 103 is arranged in the cavity of the mold so that the distal end of the removing handle 108 extends out of the slit 107. A molding material, such as rubber, is injected into the cavity. This molds the molded portion 101. After the molded portion 101 is formed, the molded portion 101 is removed from the mold. Then, the removing handle 108 is pulled to remove the core 103 out of the hollow seal 102 through the slit 107.
Further, there are vehicles that have a garnish attached around the lower half of a door opening (i.e., the portion lower than the belt line of a door). In such a vehicle, a plurality of weather strips are attached on the vehicle body around the door opening so that the weather strips maintain satisfactory seal along the entire periphery of the door opening. One type of such weather strips includes a single extruded portion, which is similar to that of the weather strip of the first related art example, and the molded portions, which are connected to both ends of the extruded portion. Each molded portion includes a hollow seal and a trim, which are formed continuously from the extruded portion. The hollow seal of the molded portion has a curved portion, the amount of projection from the trim of which decreases gradually at positions closer to the end of the weather strip (second related art example).
To mold the molded portion of the second related art weather strip, a core similar to that used in the first related art weather strip example must be arranged in the cavity of the mold. Further, a slit must be provided in the hollow seal of the molded portion or extruded portion. The slit is normally located in a side wall of the hollow seal.
However, the slit 107, which is provided in the side wall 102a of the hollow seal 102 in the molded portion or the extruded portion, decreases the rigidity of the hollow seal 102. This locally decreases the sealing capability of the weather strip.
To solve such problem, an adhesive may be used to bond the slit 107 after the core 103 is removed. However, the application of such adhesive is burdensome since thin, flexible lips, which are located on each side of the slit 107, must be bonded to each other as described below. This increases manufacturing costs.
In addition, the hollow seal 102 is designed so that it is highly elastic in order to obtain the required sealing capability. Thus, when lips 109 located on each side of the slit 107 are adhered together, the lips 109 may not be aligned with each other, as shown in FIG. 13. When the weather strip is attached to the vehicle body around a door opening with its lips 109 adhered to each other in a non-aligned state, the hollow seal 102 may become undulated. This would cause the appearance of the weather strip to be undesirable.
To prevent the undulating of the hollow seal 102, the lips 109 must be adhered together so that their surfaces are flush to each other. This requires accurate positioning of the lips 109. In such case, the adhering of the lips 109 would become burdensome and increase manufacturing costs.
It is especially difficult to adhere the lips 109 in the second related art weather strip when the lips 109 are formed on the curved portion. Further, when the lips 109 of the curved portion are adhered to each other, a force acting to tear the adhered portion is applied to the weather strip.